The present invention relates to a magnetic element that is applied to, for example, a novel functional element for use in wireless signal transmission and communication.
Recently, attention has been focused on the field of spintronics utilizing charges and spins of electrons at the same time instead of the field of electronics employing charges of electrons (Non-Patent Reference 1). The spintronics greatly contributes to the industry in the form of a hard disk drive (HDD) and a magnetoresistive memory (MRAM) with quick development of magnetoresistive effect elements based on magnetoresistive effects that are represented by a giant magnetoresistive (GMR) effect and a tunneling magnetoresistive (TMR) effect.
Regarding a magnetoresistive effect element, it is known that, through transfer and transport of a spin of one ferromagnetic substance, energy (spin-transfer torque) to rotate a spin of the other ferromagnetic substance is generated. When the spin-transfer torque and torque caused by an external magnetic field are brought into the condition of being close to each other, a spin oscillation and resonance phenomenon occurs. Utilizing such a phenomenon in industrial fields as devices for oscillation and detection, a mixer, a filter, etc. in the high-frequency range has been proposed (Patent Reference 1). It is also known that high-frequency characteristics of the magnetoresistive effect element are controlled by the applied magnetic field and the spin-transfer torque (Non-Patent Reference 2).
An element (hereinafter referred to as a “magnetic element”) utilizing high-frequency characteristics of the magnetoresistive effect element can be controlled by the applied magnetic field as mentioned above. Considering an application to the industrial field, however, the magnetic element is required to have an element structure that includes a magnetic field applying mechanism capable of variably controlling the intensity and the direction of the applied magnetic field over a wide range.
As one example of the element structure including the magnetic field applying mechanism for variably controlling the intensity of the applied magnetic field, there is proposed a structure for applying a coil magnetic field, which is generated through current control, to a magnetoresistive effect film (Patent Reference 2).
Furthermore, as one example of the element structure including the magnetic field applying mechanism for variably controlling the direction of the applied magnetic field, there is proposed an element structure including a bias magnetic field applying unit, and an adjustment-purpose magnetic field applying unit that is disposed in a direction different from the direction of a bias magnetic field (Patent Reference 3).